1. Field of the Invention
The present invention relates generally to video projection systems, and particularly to front projection video systems that can be oriented in various mounting configurations with respect to a projection surface on which an image is projected.
2. Description of the Related Art
Front projection video systems are widely used for business presentations and home entertainment viewing. The projectors of such systems typically include a light source and a display device that create the desired optical image, which is then projected through a lens for viewing on a projection surface. The projector and the projection surface are two separate objects that can be oriented differently with respect to each other.
For example, the projector 10 can be placed on a horizontal surface 11, such as a table top, as shown in FIG. 1, with the lens 12 of the projector 10 facing toward the projection surface 13. Typically a bottom or “mounting” side 14 of the projector 10 in this configuration has adjustable support feet for adjusting the elevation and tilt of the projector 10 to match the direction of the lens 12 with the projection surface 13. As shown in FIG. 2, the projector 10 can also be placed offset to one side or the other of a line perpendicular to the center of the projection surface 13. The projector 10 typically includes an image processor for adjusting horizontal and vertical trapezoidal distortion created by offset placement of the projector 10 relative to the projection surface 13 to maintain a rectangular image on the projection surface 13.
In another common mounting configuration, the projector 10 can be attached upside down to a ceiling 15, as shown in FIG. 3, with the lens 12 of the projector 10 facing toward the projection surface 13. The mounting side 14 of the projector 10 (i.e., the top side in the mounting configuration shown in FIG. 3) is typically attached to a suitable bracket on the ceiling 15, which allows the projector 10 to be adjusted for proper elevation and tilt. The image processor of the projector 10 typically includes an image flip feature that can be set to flip the video image horizontally and vertically to accommodate the upside down mounting of the projector 10.
Almost all projectors on the market today require a horizontal mounting of the projector on either a table or a ceiling, as shown in FIGS. 1 to 3. In these mounting configurations, the projector 10 is positioned with the optical axis of the lens facing toward (i.e., aimed at) the projection surface 13. However, the current trend in home design is for higher ceilings in the home, which can make ceiling-mounted projectors impractical as well as unsightly to have the mounting apparatus hanging from the ceiling. Projectors have also been attached to walls using a shelf supported on the wall, a cantilever projecting from the wall or a metal strut hanging from the wall. However, projectors have not had the additional mounting option of being attached to a wall with the optical axis of the projector lens parallel to the wall (i.e., with the lens facing in a direction other than toward the projection surface). Thus, there is a need in the industry for an improved video projection system that provides additional mounting options for the projector.